Regulation Flashcards
How does micro electrode measure pH?
2 micro electrodes measure the membrane potential and one of them measures everything but the protons as has proton sensitive resin so measures voltage difference between V1 and V2, changes in voltage is proportional to changes in pH so calibrate it to convert voltage to pH
How do you calibrate fluorescent indicators?
Add proton ionophore to membrane to permeabilise it causes pH surround it to equal intra pH
How do fluorescent indicators measure pH?
Put in to cell in its inactive form, indicator is excited with light of specific wavelength and the amount of light emitted fluorescent light at a second wavelength is measured - flourescence is proportional to intracellular pH
What is buffering power?
The amount of strong base that must be added to a solution in order to raise pH by a given amount
What makes NHE active or inactive?
A set point- of alkaline=inactive and vice versa
What is the function of NHE1?
Housekeeping function, regulation of pH and cell volume
What inhibits NHE1?
Low concentrations of amiloride and its analogue EIPA
Where is NHE1?
Basolateral membrane of epithelial cells
How many subtypes does the AE family have?
4
What are all isoforms of the AE family inhibited by?
Stilbene derivative drug DIDs
What happens if the Sodium potassium pump was removed from the thick ascending limb cell?
Diuresis (more urine) and increase sodium and chloride
What inhibits the Sodium Potassium pump?
Cardiac glycoside ouabain and digoxin
What is the role of the Sodium Potassium pump?
Electrogenic - makes inside more negative but mainly accumulation of Potassium inside creates driving force for Potassium to leave to make cell more negative
How do Sodium/ Calcium exchangers work?
Calcium binding domains (CBD1+CBD20, conformational change when calcium outside acts as a messenger, Sodium in and calcium out
What are the 3 types of Calcium pumps?
SERCA, SPCA, PMCA
